PB2187: ARTERIAL AND VENOUS THROMBOEMBOLIC COMPLICATIONS IN 832 PATIENTS WITH BCR-ABL-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS (MPN)
Authors: Kai Wille, Eva Deventer, Parvis Sadjadian, Tatjana Becker, Vera Kolatzki, Karlo Hünerbein, Raphael Meixner, Hanna Marchi, Christiane Fuchs, Martin Griesshammer
Journal: HemaSphere (2023)

Topic: 16. Myeloproliferative neoplasms - Clinical Background: Arterial (ATE) and venous (VTE) thromboembolic complications are common causes of morbidity and mortality in BCR-ABL-negative myeloproliferative neoplasms (MPN). Several studies have reported an up to 10-fold higher incidence of such complications compared to the healthy population, but precise data are scare. Regarding MPN-associated VTE, some studies showed incidence rates of 0.5% - 3.7% patient/year, with VTE mainly localised at “unusual” sites such as splanchnic or cerebral venous thrombosis. MPN-associated ATE appears to be less common, with reported incidences of about 0.2% - 1.5% patient/year. Although thromboembolic complications are frequent in MPN, there are still limited data on the distribution and incidence rates of MPN-associated ATE/VTE. Aims: This retrospective, single center study included 832 MPN patients to obtain data on the incidence rates and locations of ATE/VTE. Methods: The data of all 832 MPN patients (pts) in our institution were collected. All MPNs were diagnosed according to the currently valid WHO criteria. In a next step, those patients were selected who had suffered from an ATE and/or a VTE associated to MPN. A thromboembolic complication related to an MPN was defined as an ATE/VTE that occurred up to two years before the MPN diagnosis or afterwards. The differences in proportions were estimated using Chi square test (statistical significance threshold: p<0.05). Results: Of the 832 MPN pts, in 181 (21.8%) pts a total count of n=272 ATE/VTE occur during a median follow-up period of 5.6 years per patient (range 0.1 - 31.8). The incidence rate for all ATE/VTE was 3.11% patient/year. Considering only the first 181 thromboembolic complications, the incidence rate for the first n=105 (58.0%) VTE was 1.20% patient/year. The two most common VTE localisations were deep vein thrombosis (DVT) and/or pulmonary embolism (PE) (n=42, incidence rate: 0.48% per patient/year) and splanchnic thrombosis (n=39, 0.45% per patient/year). The incidence rate for the 76 (42.0%) first ATE was 0.87% patient/year and for the two most common ATE localisations TIA (n=23) and stroke (n=24) 0.26% and 0.27% patient/year, respectively. When comparing the group of patients with an ATE/VTE (n=181) and the group without an ATE/VTE (n=651), no significant difference was observed with regard to median age at MPN diagnosis or gender. Regarding the different MPN subtypes, statistically significantly more patients with polycythemia vera (PV) pts were diagnosed with ATE/VTE (p=0.003). In contrast, the group of patients without ATE/VTE included significantly more patients with essential thrombocythemia (p=0.010) or prefibrotic myelofibrosis (p=0.036) in. The JAK2 mutation was detected in 81.2% (n=147) of the 181 MPN patients with VTE/ATE. The remaining ATE/VTE patients had a CALR mutation (5.0%) or MPL (2.8%) and 3.9 % were “triple negative”. Compared to the 651 pts without VTE/ATE, the JAK2 mutation was significantly more frequent in pts with a thromboembolic complication (p < 0.001). Summary/Conclusion: The incidence rate for the first VTE and ATE events was 2.07% per patient/year in the entire collective of 832 MPN patients. The incidence rate of venous thrombosis was higher than that of arterial thrombosis (1,20% versus 0,87% per patient/year). The most common thromboembolic sites were DVT/PE and TIA, respectively. Significantly more patients with ATE/VTE were diagnosed with PV and/or carried the JAK2 mutation. Keywords: Myeloproliferative disorder, Thromboembolic events